I too am mystified by the all-encompassing statement by Marc Small that
the Japanese do not have the raw materials and thus do not make their
optical glass.
No doubt some companies in Japan buy glass from others. But the raw
materials to make glass are available to all, even when we are talking
about the exotic glasses. Canon, which pioneered lenses with fluorite
elements (such as the superb 300mm 2.8), made the glass for those early
classics and still makes glass.
And I am reminded in the 1970s when I photographed the last countrywide
article in National Geographic on Japan that I spent several extremely
interesting days inside Minolta factories. They proudly showed me their
glass-making operation from start to finish; from mixing raw materials,
to melting, to chunks of glass, to blanks, to polishing, to assembly.
They certainly were not buying glass from Europe or elsewhere.
I think this thread should best be laid to rest.
Fred Ward